Translated with DeepL
Lea, Simon, Laura and Luca, four teenagers, are travelling to and on the lake. A lot of technology is involved.
Complete edition (in German)
Gyro sensors convert rotational movements or changes in position into electrical voltage. If you lean forwards on the hoverboard, this is registered by the gyro sensor and signalled to the main board. The motors then rotate forwards faster so that the board remains under your centre of gravity and you don't lose your balance.
There are different types of gyro sensors or gyroscopes. A vibrating gyroscope, such as those found in hoverboards, determines the extent of the rotational movement via a vibrating structure (e.g. a quartz crystal). The crystal oscillates in the original plane, even if its support rotates. The Coriolis effect causes the vibrating structure to exert a force on its support, which can be measured and provides information about the rotational movement.
Gyro sensors are available in various electronic devices. When you rotate your smartphone or tablet, the gyro sensor registers the change in position and the image switches from portrait to landscape format. Digital cameras (for image stabilisation), remote-controlled model helicopters and games consoles can also be equipped with gyro sensors.
A wooden cube floats on water, while an iron cube of the same size sinks. Is this only due to the difference in weight? No, because if you build a ship from the iron in the cube, it won't sink. This is because a ship of the same weight has a much larger volume than an iron cube. The Greek mathematician, physicist and engineer Archimedes of Syracuse established as early as 215 BC that a body in water experiences a buoyant force that is equal to the weight of the displaced water. If the weight of the displaced water is greater than the weight of the body (ship), then it floats. For a homogeneous body, the density (mass/volume) of the material must be less than the density of the water. The wood of the cube has a lower density than the water (floats), iron has a higher density (does not float).
If you want to know more precisely:
ρKö: Density of the body
ρFl: Density of the liquid
V: Volume of the body or the displaced liquid
g: acceleration due to gravity (= 9.81 m-s-2)
FA (buoyancy) = ρFl × V × g
G (weight) = ρKö×V × g
| Sinks | Floats | Rises | |
| Forces | G >FA | G =FA | G <FA |
| Densities | ρKö > ρFl | ρKö = ρFl | ρKö < ρFl |
Concrete is not really a buoyant material. And yet there are ships made of concrete. Concrete is relatively cheap, very robust and concrete ships require less maintenance. However, concrete ships are heavier, which makes them more expensive to operate, and less manoeuvrable. They are therefore the exception rather than the rule. However, concrete boat building competitions are regularly held at universities and technical colleges.
Electric hoverboards are only authorised for use on public property if they meet certain conditions, e.g. a maximum total motor power of 2.00 kW, which is used to a significant extent for maintaining the balance of the vehicle, and a maximum design speed of 20 km/h or less. Further conditions and information can be found in the "Ordinance on the technical requirements for road vehicles".
Technoscope is SATW's technology magazine for young people. It reports competently and entertainingly on technology and technical professions. Technoscope is published three times a year in German, French and Italian. It can be subscribed to free of charge. Existing issues can be downloaded as PDF files.
Beatrice Huber
Christine D'Anna-Huber, Alexandra Rosakis
